Vector Quantization for License-Plate Location and Image Coding

Rodolfo Zunino, Member, IEEE, and Stefano Rovetta, Member, IEEE



Abstract

License-plate location in sensor images plays an important
role in vehicle identification for automated transport
systems (ATS’s). This paper presents a novel method based on
vector quantization (VQ) to process vehicle images. The proposed
method makes it possible to perform superior picture compression
for archival purposes and to support effective location at the same
time. As compared with classical approaches, VQ encoding can
give some hints about the contents of image regions; such additional
information can be exploited to boost location performance.
The VQ system can be trained by way of examples; this gives the
advantages of adaptiveness and on-field tuning. The approach
has been tested in a real industrial application and included
satisfactorily in a complete ATS for vehicle identification.



Index Terms

Image analysis, image coding, road vehicle identification,
vector quantization.


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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS,
VOL. 47, NO. 1, FEBRUARY 2000, pp. 159-167